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authorWolfram Sang <wsa+renesas@sang-engineering.com>2014-05-02 21:15:16 +0200
committerWolfram Sang <wsa@the-dreams.de>2014-05-22 10:09:25 +0200
commit67240dfcb8dcf756cc00fb37f5cb7e3ee2fa6190 (patch)
tree998fac70bb3516601d0492e6468f30bb4bfb75ed /drivers/i2c
parent7663ebefca8079ef0fd2fff1047d3d10af654c78 (diff)
i2c: sh_mobile: fix clock calculation for newer SoCs
Newer SoCs have so fast input clocks that the ICCL/H registers only count every second clock to have a meaningful 9-bit range. The driver was already prepared for that happening, but didn't use it so far. Add the proper DT configuration for SoCs that need it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-sh_mobile.c48
1 files changed, 38 insertions, 10 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index b1d399e3e5fc..c29be2bba6ea 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -32,6 +32,7 @@
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/of_device.h>
#include <linux/i2c/i2c-sh_mobile.h>
/* Transmit operation: */
@@ -139,6 +140,10 @@ struct sh_mobile_i2c_data {
bool send_stop;
};
+struct sh_mobile_dt_config {
+ int clks_per_count;
+};
+
#define IIC_FLAG_HAS_ICIC67 (1 << 0)
#define STANDARD_MODE 100000
@@ -617,6 +622,22 @@ static struct i2c_algorithm sh_mobile_i2c_algorithm = {
.master_xfer = sh_mobile_i2c_xfer,
};
+static const struct sh_mobile_dt_config default_dt_config = {
+ .clks_per_count = 1,
+};
+
+static const struct sh_mobile_dt_config rcar_gen2_dt_config = {
+ .clks_per_count = 2,
+};
+
+static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
+ { .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
+ { .compatible = "renesas,iic-r8a7790", .data = &rcar_gen2_dt_config },
+ { .compatible = "renesas,iic-r8a7791", .data = &rcar_gen2_dt_config },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
+
static int sh_mobile_i2c_hook_irqs(struct platform_device *dev)
{
struct resource *res;
@@ -674,11 +695,24 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed);
pd->bus_speed = ret ? STANDARD_MODE : bus_speed;
- if (pdata && pdata->bus_speed)
- pd->bus_speed = pdata->bus_speed;
pd->clks_per_count = 1;
- if (pdata && pdata->clks_per_count)
- pd->clks_per_count = pdata->clks_per_count;
+
+ if (dev->dev.of_node) {
+ const struct of_device_id *match;
+
+ match = of_match_device(sh_mobile_i2c_dt_ids, &dev->dev);
+ if (match) {
+ const struct sh_mobile_dt_config *config;
+
+ config = match->data;
+ pd->clks_per_count = config->clks_per_count;
+ }
+ } else {
+ if (pdata && pdata->bus_speed)
+ pd->bus_speed = pdata->bus_speed;
+ if (pdata && pdata->clks_per_count)
+ pd->clks_per_count = pdata->clks_per_count;
+ }
/* The IIC blocks on SH-Mobile ARM processors
* come with two new bits in ICIC.
@@ -758,12 +792,6 @@ static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
.runtime_resume = sh_mobile_i2c_runtime_nop,
};
-static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
- { .compatible = "renesas,rmobile-iic", },
- {},
-};
-MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
-
static struct platform_driver sh_mobile_i2c_driver = {
.driver = {
.name = "i2c-sh_mobile",